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fea681da | 1 | .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
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2 | .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk |
3 | .\" <mtk.manpages@gmail.com> | |
fea681da | 4 | .\" |
93015253 | 5 | .\" %%%LICENSE_START(VERBATIM) |
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6 | .\" Permission is granted to make and distribute verbatim copies of this |
7 | .\" manual provided the copyright notice and this permission notice are | |
8 | .\" preserved on all copies. | |
9 | .\" | |
10 | .\" Permission is granted to copy and distribute modified versions of this | |
11 | .\" manual under the conditions for verbatim copying, provided that the | |
12 | .\" entire resulting derived work is distributed under the terms of a | |
13 | .\" permission notice identical to this one. | |
c13182ef | 14 | .\" |
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15 | .\" Since the Linux kernel and libraries are constantly changing, this |
16 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
17 | .\" responsibility for errors or omissions, or for damages resulting from | |
18 | .\" the use of the information contained herein. The author(s) may not | |
19 | .\" have taken the same level of care in the production of this manual, | |
20 | .\" which is licensed free of charge, as they might when working | |
21 | .\" professionally. | |
c13182ef | 22 | .\" |
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23 | .\" Formatted or processed versions of this manual, if unaccompanied by |
24 | .\" the source, must acknowledge the copyright and authors of this work. | |
4b72fb64 | 25 | .\" %%%LICENSE_END |
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26 | .\" |
27 | .\" References consulted: | |
28 | .\" Linux libc source code | |
29 | .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) | |
30 | .\" 386BSD man pages | |
31 | .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) | |
32 | .\" Modified 2002-07-27 by Walter Harms | |
33 | .\" (walter.harms@informatik.uni-oldenburg.de) | |
4b8c67d9 | 34 | .TH SQRT 3 2017-09-15 "" "Linux Programmer's Manual" |
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35 | .SH NAME |
36 | sqrt, sqrtf, sqrtl \- square root function | |
37 | .SH SYNOPSIS | |
38 | .nf | |
39 | .B #include <math.h> | |
68e4db0a | 40 | .PP |
fea681da | 41 | .BI "double sqrt(double " x ); |
fea681da | 42 | .BI "float sqrtf(float " x ); |
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43 | .BI "long double sqrtl(long double " x ); |
44 | .fi | |
68e4db0a | 45 | .PP |
20c58d70 | 46 | Link with \fI\-lm\fP. |
68e4db0a | 47 | .PP |
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48 | .in -4n |
49 | Feature Test Macro Requirements for glibc (see | |
50 | .BR feature_test_macros (7)): | |
51 | .in | |
68e4db0a | 52 | .PP |
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53 | .ad l |
54 | .BR sqrtf (), | |
55 | .BR sqrtl (): | |
b90c43a8 | 56 | .RS 4 |
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57 | _ISOC99_SOURCE || _POSIX_C_SOURCE\ >=\ 200112L |
58 | || /* Since glibc 2.19: */ _DEFAULT_SOURCE | |
59 | || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE | |
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60 | .RE |
61 | .ad | |
fea681da | 62 | .SH DESCRIPTION |
5600f73a | 63 | These functions return the nonnegative square root of |
022671eb | 64 | .IR x . |
47297adb | 65 | .SH RETURN VALUE |
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66 | On success, these functions return the square root of |
67 | .IR x . | |
847e0d88 | 68 | .PP |
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69 | If |
70 | .I x | |
71 | is a NaN, a NaN is returned. | |
847e0d88 | 72 | .PP |
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73 | If |
74 | .I x | |
75 | is +0 (\-0), +0 (\-0) is returned. | |
847e0d88 | 76 | .PP |
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77 | If |
78 | .I x | |
79 | is positive infinity, positive infinity is returned. | |
847e0d88 | 80 | .PP |
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81 | If |
82 | .I x | |
83 | is less than \-0, | |
efe294cb | 84 | a domain error occurs, |
631c6898 | 85 | and a NaN is returned. |
fea681da | 86 | .SH ERRORS |
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87 | See |
88 | .BR math_error (7) | |
89 | for information on how to determine whether an error has occurred | |
90 | when calling these functions. | |
91 | .PP | |
92 | The following errors can occur: | |
fea681da | 93 | .TP |
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94 | Domain error: \fIx\fP less than \-0 |
95 | .I errno | |
96 | is set to | |
97 | .BR EDOM . | |
98 | An invalid floating-point exception | |
99 | .RB ( FE_INVALID ) | |
100 | is raised. | |
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101 | .SH ATTRIBUTES |
102 | For an explanation of the terms used in this section, see | |
103 | .BR attributes (7). | |
104 | .TS | |
105 | allbox; | |
106 | lbw24 lb lb | |
107 | l l l. | |
108 | Interface Attribute Value | |
109 | T{ | |
110 | .BR sqrt (), | |
111 | .BR sqrtf (), | |
112 | .BR sqrtl () | |
113 | T} Thread safety MT-Safe | |
114 | .TE | |
47297adb | 115 | .SH CONFORMING TO |
9a74e018 | 116 | C99, POSIX.1-2001, POSIX.1-2008. |
847e0d88 | 117 | .PP |
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118 | The variant returning |
119 | .I double | |
120 | also conforms to | |
68e1685c | 121 | SVr4, 4.3BSD, C89. |
47297adb | 122 | .SH SEE ALSO |
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123 | .BR cbrt (3), |
124 | .BR csqrt (3), | |
fea681da | 125 | .BR hypot (3) |